Thurman defeats Bundu in 12 rounds

LAS VEGAS -- Keith Thurman may have won the battle by outboxing an awkward Leonard Bundu on Saturday, but he clearly lost the war when it came to announcing himself as an attractive candidate to face Floyd Mayweather Jr.

Thurman (24-0, 21 KOs), who aggressively called out Mayweather at Friday's weigh-in, put forth a patient, technical performance to outlast a tough Bundu by shutout scores of 120-107 on all three cards in the co-main event of the Amir Khan-Devon Alexander welterweight bout at the MGM Grand Garden Arena.

But Thurman, nicknamed "One Time," was unable to come through on his promise of a knockout. In fact, he backpedaled for the majority of the bout, drawing boos from those in attendance throughout.

"This is the sport of boxing. I pick how I want to fight," Thurman said. "I felt rusty from being off for eight months. I decided to keep boxing and not go for the knockout. It was really good for me to hang in there and get the 12 rounds of experience.

"[Bundu] was hard to fight. He's a live veteran. I learned that I need to work on being able to go after a knockout and not just sit back and counter."

Bundu (31-1-2, 11 KOs) utilized an awkward rhythm to constantly switch stances and make things difficult. While Thurman deserves credit for a mature boxing performance and never overextending himself, he allowed the light-hitting Bundu, 40, to be the aggressor throughout.

"I'm happy with my performance," Bundu said. "He was moving too much. He's a good puncher. He has power. But he shouldn't be there waiting for me."

Thurman knocked Bundu down with the first significant punch he landed in Round 1. After Italy's Bundu switched to a southpaw stance, Thurman instantly adjusted by doing the same thing and floored Bundu on a perfect counter left hand.

"I got surprised in the first round when he dropped me," Bundu said. "I figured I would run him out but he's a good fighter and he's young."

Thurman switched gears after the fight and called out fellow welterweight Marcos Maidana, who was ringside, drawing an outpouring of boos from the crowd.

Mares stops Ramirez in all-action bout

Abner Mares' reunion with trainer Clemente Medina proved to be an exciting one for the fans.

Abner Mares, left, returned to the ring in December with an impressive victory over Jose Ramirez. Ed Mulholland/Golden Boy/Getty Images

A former three-division titlist, Mares channeled the aggressive style that helped him build his name by dropping Jose Ramirez three times and stopping him in a late addition to the fight of the year conversation.

"I expected it to be a war and he made it a war," Mares said. "I needed these rounds. He was a tough guy. I wanted to start fast and I think I did that. I wanted to show that just because I was knocked out once, it doesn't mean I can't take a punch."

Mares (28-1-1, 15 KOs), who joined forces with trainer Virgil Hunter for one fight following his August 2013 knockout loss to Jhonny Gonzalez, stood in the pocket from the opening bell and was willing to take as much as he gave.

But despite Ramirez's toughness, Mares was the bigger puncher with the better technique who routinely landed the cleaner, harder shots. Mares scored a knockdown in Round 1 following a pair of body shots and added a second knockdown in Round 3 when Ramirez was hurt by a flurry and fell into the ropes.

A Mares body shot forced Ramirez to touch a knee to the canvas in Round 4, although Reiss ruled it a slip. Mares came back the following round to floor Ramirez again on a vicious left hook. Ramirez spit out his mouthpiece to buy time and was docked an additional point.

"I'm back," said Mares, who after the bout reiterated his desire to land a rematch with Gonzalez. "I knew that I had to go to work. He took a lot of shots and I took a few and that's what the crowd wants."

Ramirez's willingness to take punishment and keep brawling brought out the best in Mares as the two traded punches in a phone booth the entire fight.

"I'm happy with my performance but not with the result," Ramirez said. "Abner Mares is a great fighter. He's No. 3 in the world and I feel honored to have fought him."

Jermall Charlo wins title eliminator

The only thing unbeaten junior middleweight contender Jermall Charlo has lacked so far in his career is a victory over a big name.

And while the Houston native didn't necessarily get that on Saturday in a title eliminator against Lenny Botai, he added a thrilling knockout to his career highlight reel.

Charlo (20-0, 16 KOs), the identical twin of fellow 154-pound prospect Jermell Charlo, knocked Bottai down and out in Round 3 with a perfect short counter hook to the head. As Bottai (22-3, 9 KOs), a native of Italy, struggled to reach his feet, referee Jay Nady waved off the bout at 38 seconds just as Bottai's corner threw in the towel.

"It was easy work," Charlo said. "I knew all week it was going to be easy work. I did exactly what [trainer] Ronnie Shields told me. Bottai wanted to get rough but I shot the hook and he ate it."

Charlo saw a March title shot with Carlos Molina fall apart in the final hour when Molina was detained over immigration issues. After Saturday's win he called out current titlist Cornelius "K9" Bundrage, who defeated Molina for his title in October.

"K9, I want you, boy. I want the IBF title," Charlo said. "The title shot is a long time coming. My brother and I have to keep our heads up. It's part of the game. It's part of boxing. We are still young."

Jermell Charlo cruises past Lozano

For whatever his bout lacked in entertainment, unbeaten junior middleweight Jermell Charlo made up for it in dominance.

The athletic Charlo (25-0, 11 KOs) put on a boxing clinic by routinely timing Mario Lozano with counter left hooks and piling up one round after another en route to a unanimous decision. All three judges scored the fight 100-90.

"I thought I was going to stop him but I got my rounds in, a win is a win," Charlo said. "I'm happy with my performance. I wanted to get the KO but he was tough."

The more Lozano (27-6, 20 KOs) stepped up the pace, the more Charlo increased his output and landed clean shots. The victory was the third of 2014 for Charlo, who defeated Gabriel Rosado in January.

Unbeaten Spence too much for Castro

Welterweight prospect Errol Spence Jr. simply couldn't miss. It was just a matter of how much referee Robert Byrd was going to allow Javier Castro to take.

Spence (15-0, 12 KOs), a blue-chip prospect and 2012 Olympian from Dallas, peppered the hard-charging Castro with everything he had before Byrd finally saw enough and stepped in at 2:43 of Round 5.

"I feel great physically and mentally," Spence said. "He's a tough, solid fighter. He didn't want to go down. I was hitting him with everything I have and the referee wasn't stopping it."

Castro (27-8, 22 KOs) was just too slow to keep up with Spence, who landed upwards of 10 unanswered shots along the ropes early in Round 5 to bloody Castro's nose. Spence landed 53 percent of his total punches, according to CompuBox.

Ortiz (30-5-2, 23 KOs), who was stopped by Luis Collazo in Round 2 of a similar comeback attempt in January, traded clean shots at close range throughout before scoring a TKO at 51 seconds of Round 3.

The much larger Ortiz landed a three-punch combination that floored Perez (21-11-1, 4 KOs) along the ropes. Referee Vic Drakulich waved the fight off after a weary Perez, with severe swelling around his left eye, reached his feet. Ortiz outlanded Perez 58 to 27 according to CompuBox.

Ortiz, who has enjoyed lengthy breaks from the ring in recent years while filming "Dancing With The Stars" and a role in the recent film "The Expendables 3," was happy with his performance in his first fight with trainer Joel Diaz.

"Up next I have a couple of movies but I'm just going to do whatever my coaches say," Ortiz said. "I'm having a good time again and looking to get back to where I left off."

Kamegai rebounds with knockout

Yoshihiro Kamegai bounced back nicely from his defeat in a fight of the year candidate in April by scoring a fourth-round knockout of Oscar Godov.

Kamegai (25-2-1, 22 KOs), one fight removed from dropping a unanimous decision to Robert Guerrero in a rousing slugfest, was aggressive throughout and struck first by flooring Godov (13-4, 6 KOs) with a right hand in Round 2. The native of Japan continued the pressure before dropping Godov for good in Round 5 as referee Jay Nady reached the count of 10 at 1:58.

Shumenov wins cruiserweight debut

Beibut Shumenov's debut in the cruiserweight division was a hit, scoring a TKO victory over Robert Thomas Jr. on Saturday. Donald Miralle/Getty Images

Former light heavyweight titlist Beibut Shumenov made a successful leap to the cruiserweight division by forcing an early stoppage against Robert Thomas Jr.

Shumenov (15-2, 9 KOs), a native of Kazakhstan who fights out of Las Vegas, hammered Thomas (14-3-1, 9 KOs) with clean power shots throughout before referee Jack Reiss called a halt to the bout before the start of Round 6.

The 2004 Olympian was making his first appearance since dropping his title by decision to Bernard Hopkins in an April unification bout.